Lemon Texas Sheet Cake

Ingredients

Cake

• 1 1/4 cups (2 1/2 sticks) unsalted butter
• 1 cup water
• 1/2 cup fresh lemon juice
• 2 1/2 cups all-purpose flour
• 2 1/2 cups sugar
• 2/3 cup sour cream
• 2 tbsp lemon zest
• 2 eggs
• 1 tsp pure vanilla extract
• 1/2 tsp pure lemon extract
• 1 1/4 tsp baking soda
• 1/2 tsp salt

Glaze

• 3 1/2 cups powdered sugar
• 6 tbsp fresh lemon juice
• 1 tbsp lemon zest

Instructions

1. Heat the oven to 375°F with a rack in the center. Butter a rimmed 18×13×1-inch half sheet pan (the big one — a 9×13 is too small for this batter).
2. Melt the butter in a large pot over medium heat, then add the water and lemon juice, raise the heat, and bring to a boil. Pull the pot off the heat and let it cool at least 5 minutes — this matters, or the batter turns too thick when the flour goes in.
3. Stir the flour briskly into the warm liquid until smooth, then work in the sugar, sour cream, and lemon zest.
4. Temper the eggs: beat them in a small bowl, then whisk in spoonfuls of the warm batter a little at a time before stirring the egg mixture back into the pot. This keeps them from scrambling. Mix in the vanilla and lemon extracts.
5. Sprinkle the baking soda and salt evenly over the batter (no lumps) and stir until everything is combined.
6. Pour into the prepared pan, smooth the top, and bake 15–18 minutes, until a toothpick from the center comes out clean. Cool the cake completely in the pan.
7. For the glaze, whisk the powdered sugar with the lemon juice and zest until smooth — thin with a splash more juice or thicken with a little more sugar as needed.
8. Pour the glaze over the cooled cake and immediately spread it into a thin, even layer. Chill uncovered at least 30 minutes so the glaze sets, then slice into squares straight from the pan. Garnish with lemon slice quarters if you’re feeling fancy.

Notes

Plan for 3–4 large lemons to cover all the juice and zest. Keep leftovers covered in the fridge; it can be made a day or two ahead — just let it sit out a bit before serving. Extra lemon juice freezes well in 1-tablespoon portions.